While I personally detest pacifism because it promises just too much for what it can actually provide (while snarkily name-calling everyone else as grotesque violent people), one should analyse it as potentially "viable" inside a narrative like BP. One must be somewhat open to the possibility that a different context like the one described where beings like Shivan and Vishnan exist can indeed turn viable such an obsolete point of view, or indeed turn the tables upside down to whatever kind of ideological truths we may hold dear in our present.
e: Think of the above in a darwinian sense. While today any pacifist nation would be "dead-on-arrival", one can create alternative universes where Shivanesque creatures select and destroy civilizations based on signals of their attitude. In such an universe, a nauseatingly naive civilization filled with kumbayah polyanna behavior would survive while a more "down-to-earth" self-defending common-sensical civilization (to our standards) would not - the first would go unnoticed or unselected, while the second would be exterminated.
This means that any "irrational behavior" can be justifiable if that behavior is rewarded by not being targeted and exterminated by the outside force. Weird behavioral branching is then allowed to exist, completely lunatic civilizations with weird irrational beliefs and actions are possibly allowed to do better than usual ones.
That's, btw, the "problem" of existing godlike creatures, it messes everything up that badly.
Furthermore, it is patently obvious that there's a lot of meddling of these gods unto the higher positions of each faction, which it even makes this whole mess even more messier. One should make the questions of whether peace was really impossible due to the reasons given by galtevs, or if it was just "made" impossible by some kind of nagari influence meddling up the anxiety levels of galtev officials. The scenario of a "proxy war" by crizza must surely have gone through every mind in this particular universe. It can be even worse: a remake of Job's life being used as a bet between god and the devil (read the bible ffs).
So there's just so much going on. Anytime the big trump card that stomps every other mortal card can be placed on the table, and all the previous analysis goes out the window.